Steel rails&amp;apos; joint fishplate made of xy30 steel

ABSTRACT

The present invention relates to a rail clip, an important fitting part, for the railway made of a new steel XY30 which is one of a high-manganese steel without nickel and which has high strength and high toughness even if it is used in the low-temperature circumstance. The rail clip is characterized in that the rail clip has the shape of a bar with a section of “ T ” and comprises a working surface, a non-working surface, a mounting surface for bolts and a non-working surface inside a web plate; the two working surfaces of a upper small surface side and a lower large surface side on the same side of the rail clip come into circular arc point contact with the railroad rail, a small circular arc is provided on the working surface which is on the upper small surface side; the upper small surface side, the lower large surface side and the non-working surface inside the web plate are connected with circular arcs; upper and lower non-working surfaces on the other side of the rail clip are perpendicular to the horizon.

FIELD OF THE INVENTION

[0001] The present invention relates to a rail clip, which is animportant fitting part for the railway made of a new steel XY30 and oneof a high-manganese steel without nickel and having high strength andhigh toughness even if it is used in the low-temperature circumstance.

DESCRIPTION OF THE RELATED ART

[0002] The rail clip is used to joint railroad rails made of the steelXY30 in the low-temperature circumstance, which is an important fittingpart to the railway, so the technical properties are strictlyprescribed. The rail clip for the railway is made of steel B₇ inaccordance with the Railway Standard TB/T2342.1˜4-93 being enacted bythe railroad department of the People's Republic of China and enteredinto force in China in 1993.

[0003] The chemistry composition of the steel B₇ is as following:

[0004] C: 0.50˜0.62%, Mn: 0.50˜0.80%, Si: 0.15˜0.35%, P:<0.045%,S<0.050%.

[0005] The mechanical properties of the steel B₇ after heat treatmentare as following:

[0006] Tensile strength σ_(b)≧785 Mpa, yield strength σ_(b)≧520 Mpa,percentage elongation δ_(s)≧9%, percentage reduction of area ≧20%,Brinell hardness HB227˜399, and being in good condition under a coldbending angle of 30°.

[0007] The mechanical properties of the rail clip for the technicalacceptance check under the normal temperature prescribed by the US AREMAStandard are as following.

[0008] Tensile strength σ_(b)≧690 Mpa, yield strength σ_(s)≧480 Mpa,percentage elongation δ_(s)≧12%, percentage reduction of area ≧28%, andbeing in good condition under a cold bending angle of d=3a, 180°.

[0009] It has been proved with the application over a long period oftime that the steel B₇ is only suitable for the normal temperature to−20° C. The steel B₇ is apt to rupture when it is used under a lowtemperature, so that the railway is adversely affected due to rupturefailures which are often occurring at trunk railways since there is agreat deal of temperature differences among provinces. Recently thesteel B₇ no longer satisfies the requirement necessary for the rail clipsince the mechanical properties of the rail clip should be improved tomatch the increasing speed of the railway communication.

SUMMARY OF THE INVENTION

[0010] The object of the present invention is to provide a rail clipused for railway and made of the steel XY30, the rail clip has improvedlow temperature properties, e.g. high strength and toughness under a lowtemperature.

[0011] In order to achieve the above object, the present inventionprovides a steel which is based on a high manganese steel into whichappropriate amount of Mo (molybdenum) and V (vanadium), Nb (Niobium), Al(Aluminum) and rare earth element in minute quantities are added.

[0012] The rail clip or joint bar made of the steel XY30 according topresent invention is as following.

[0013] The rail clip according to present invention is characterized inthat the rail clip is made of the steel XY30, the chemistry compositionof the steel XY30 is as following (%): C: 0.28˜0.34, Mn: 1.30˜1.50, Si:0.15˜0.35, P<0.030, S<0.030, Mo: 0.25˜0.35, V: 0.10˜0.25, Al: 0.015, Nb:0.05˜0.10, Re: 0.040˜0.20, Cu<0.20; the rail clip has a shape of a barwith a section of “T”, the rail clip comprising: a working surface, anon-working surface, a mounting surface for mounting bolts and anon-working surface inside a web plate; a small circular arc is providedon the working surface which is on an upper small surface side on thesame side of the rail clip; the upper small surface, a lower largesurface and the non-working surface inside the web plate are connectedwith circular arcs; upper and lower non-working surfaces on the otherside of the rail clip are perpendicular to the horizon.

[0014] The rail clip being an important fitting part for the railwaymade of the steel XY30 and used for rails according to present inventionis designed for the rails of the high-speed railway. The strength andtoughness of the rail clip of the present invention under a lowtemperature are increased since the rail clip is made of the steel XY30.Through the detection and application test of the national research &analysis center of materials of China, the rail clip can be used underthe temperature of −60˜30° C. with high strength and toughness andwithout crack and rupture, and the service life of the rail clip isincreased by 1.5˜2 times. Therefore, the rail clip is adapted to railsused in the developing high-speed railway.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015]FIG. 1 is a schematic view showing the working surface structureof the rail clip made of steel XY30 for railroad rails according topresent invention; where 1—a working surface of the rail clip forrailroad rails; 2—a non-working surface; 3—a working surface for bolts;4—a non-working surface inside a web plate.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] As shown in the FIG. 1, the rail clip made of steel XY30 forrailroad rails according to present invention is achieved as following,the chemistry composition of the steel XY30 is as following (%): C:0.28˜0.34, Mn: 1.30˜1.50, Si: 0.15˜0.35, P<0.030, S<0.030, Mo:0.25˜0.35, V: 0.10˜0.25, Al: 0.015, Nb: 0.05˜0.10, Re: 0.040˜0.20,Cu<0.20. The rail clip has a shape of a bar with a section of “T”, therail clip comprising: a working surface 1, a non-working surface 2, amounting surface for bolts 3 and a non-working surface inside a webplate 4. The two working surfaces 1 on an upper small surface side and alower large surface side on the same side of the rail clip come intocircular arc point contact with the railroad rail. The contactingcircular arcs of the working surfaces of the upper small surface have aradius of R₂═R19.05 mm and a radius of R₁═R9.526 mm, respectively, whilethe contacting circular arcs of the working surfaces of the lower largesurface have a radius of R₆═R355.6 mm and a radius of R₅═R10.05 mm,respectively. The connecting circular arc connecting the upper smallsurface with the non-working surface inside the web plate 4 has a radiusof R₃═R25.4 mm, the connecting circular arc connecting the lower largesurface with the non-working surface inside the web plate 4 have aradius of R₄═R14.287 mm. The upper and lower non-working surfaces 2 onthe other side of the rail clip are perpendicular to the horizon, theupper non-working surface is projected from the mounting surface forbolts 3 with H₁=15.875 mm, the lower non-working surface is projectedfrom the mounting surface for bolts 3 with H₂=22.225 mm. A smallcircular arc is provided at the center along the length of the workingsurface of the upper small surface (that is, along the directionperpendicular to the cross section shown in the FIG. 1). The smallcircular arc has a width of 54.9 mm along the length of the workingsurfaces of the upper small surface, and a radius of R101.6 mmperpendicular to the working surfaces of the upper small surface, adepth of 1.190 mm with respect to the working surfaces of the uppersmall surface. The small circular arc is extended from the center of thecircular arc corresponding to the R₁, to its point of tangency where thesmall circular arc is tangental to the circular arc corresponding to theR₃, via the circular arc corresponding to the R₂. The small circular arcis located at the gap between the joint ends of two rails when the railsare installed, so that the shearing force of the cross section can beeliminated when the joint ends of two rails are bend downwards.

What is claimed is:
 1. A rail clip for railroad rails is characterizedin that the rail clip is made of the steel XY30, the chemistrycomposition of the steel XY30 is as following (%): C: 0.28˜0.34, Mn:1.30˜1.50, Si: 0.15˜0.35, P<0.030, S<0.030, Mo: 0.25˜0.35, V: 0.10˜0.25,Al: 0.015, Nb: 0.05˜0.10, Re: 0.040˜0.20, Cu<0.20; the rail clip has ashape of a bar with a section of “T”, the rail clip comprising: aworking surface, a non-working surface, a mounting surface for mountingbolts and a non-working surface inside a web plate; the two workingsurfaces on an upper small surface side and a lower large surface sideon the same side of the rail clip come into circular arc point contactwith the railroad rail, a small circular arc is provided on the workingsurface which is on the upper small surface side; the upper smallsurface, the lower large surface and the non-working surface inside theweb plate are connected with circular arcs.
 2. The rail clip forrailroad rails as claimed in the claim 1 is characterized in that thecontacting circular arcs of the working surfaces of the upper smallsurface have a radius of R₂=19.05 mm and a radius of R₁═R9.526 mm,respectively, while the contacting circular arcs of the working surfacesof the lower large surface have a radius of R₆═R355.6 mm and a radius ofR₅═R10.05 mm, respectively, the connecting circular arc connecting theupper small surface with the non-working surface inside the web plate 4has a radius of R₃═R 25.4 mm, the connecting circular arc connecting thelower large surface with the non-working surface inside the web plate 4have a radius of R₄═R14.287 mm; the upper and lower non-working surfaceson the other side of the rail clip are perpendicular to the horizon, theupper non-working surface is projected from the mounting surface formounting bolts with H₁=15.875 mm, the lower non-working surface isprojected from the mounting surface for mounting bolts with H₂=22.225mm.
 3. The rail clip for railroad rails as claimed in the claim 1 ischaracterized in that a small circular arc is provided at the centeralong the length of the working surfaces of the upper small surface, thesmall circular arc has a width of 54.9 mm along the length of theworking surface of the upper small surface, and a radius of R101.6 mmperpendicular to the working surfaces of the upper small surface, adepth of 1.190 mm with respect to the working surfaces of the uppersmall surface, the small circular arc is extended from the center of thecircular arc corresponding to the R₁, to its point of tangency where thesmall circular arc is tangental to the circular arc corresponding to theR₃, via the circular arc corresponding to the R₂.
 4. The rail clip forrailroad rails as claimed in the claim 1 is characterized in that upperand lower non-working surfaces on the other side of the rail clip areperpendicular to the horizon.